1. Field of the Invention
This invention relates to an ultrasonic surgical scalpel capable of effectively shattering subcutaneous or organic tissues of a living body into its mushy state by use of ultrasonic vibrations and sucking out the shattered tissues by use of sucking force.
2. Description of the Prior Art
There has been well known an ultrasonic surgical scalpel for use in a plastic surgical operation to remove subcutaneous adipose tissues or an organic surgery to remove liver or other organic tissues and so on, which comprises an ultrasonic vibrator incorporated in a handpiece and a hollow horn connected to the vibrator Vibrations generated by the vibrator are magnified in amplitude in a matter of two times to several ten times when propagating from the basal end attached to the vibrator to the leading end of the horn.
When performing the plastic surgical operation to remove, for example, subcutaneous adipose tissues of a patient's body, the leading end of the aforesaid scalpel horn is inserted into under the skin of the patient's body, and then, the vibrator is driven to vibrate the horn so as to shatter the subcutaneous adipose tissues into its mushy state. While shattering the subcutaneous tissues with ultrasonic vibrations generated by the vibrator, sucking force is applied to inside the hollow horn to suck out the subcutaneous tissues shattered into the mushy state as noted above through a suction passage in the horn. Thus, the subcutaneous tissues can be shattered with the ultrasonic vibrations and removed out of the patient's body through the horn.
In the prior art ultrasonic scalpel, the hollow horn is used as a suction tube through which the shattered tissues or fat in the mushy state are sucked out and provided in its leading end with a suction mouth. In a general way, this suction mouth is open just frontward in the axial (lengthwise) direction of the horn. That is, the secant plane defining the mouth at the leading end of the horn perpendicularly intersects the axis of the horn. This conventional ultrasonic scalpel has however entailed a disadvantage that it produces relatively large resistance when being inserted into the subcutaneous or organic tissues so as to advance against the tissues with difficulty because the secant plane forming the mouth is perpendicular to the axis of the horn. This is one of the reasons why the surgical operation is difficult. Besides, forcible insertion of the horn into the subcutaneous or organic tissues causes blood vessels, nerve tissues and so on to be injured needlessly, consequently to elongate the period for healing an operation wound.
Particularly in a case of inserting the scalpel horn into between the skin and the subcutaneous tissue of the living body, the scalpel horn cannot be moved forward along the inner surface of the skin in a desired direction and is apt to advance into the subcutaneous tissue, because the suction mouth is open straight frontward in the axial direction of the horn.
Furthermore, the conventional ultrasonic scalpel is generally connected to an external aspirator in order to aspirate subcutaneous tissues shattered into its mushy state with ultrasonic vibrations. Generally, sucking force generated by the aspirator is adjusted by operating a suction adjusting means provided on the aspirator or a suction regulating valve mounted on the handpiece. Either way, the work becomes onerous where the adjusting means or regulating valve is frequently operated to control the sucking force to be given to inside the scalpel horn in the midst of a surgical operation. Also, the surgical scalpel with the latter suction regulating valve is complicated in structure and awkward.